| Community Sediment Transport Modeling, National Ocean Partnership Program |
Dec-2009 |
|
| Authors:
Timothy R Keen; W R Geyer; Christopher R Sherwood; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF APPLIED OCEAN PHYSICS AND ENGINEERING
|
 | The goal of the Community Sediment Transport Modeling System (CSTMS) was to produce an open-source model that couples hydrodynamics (circulation and waves), sediment transport, and morphodynamics. The model is intended to be used as both a research tool and for practical applications. An accurate and useful model requires coupling sediment-transport with hydrodynamic forcing and stratigraphic evolution. Ultimately, the modeling system will consist of interoperable modules, conforming to a community-accepted standard ... |
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| Houston-Galveston Navigation Channels, Texas Project. Navigation Channel Sedimentation Study, Phase 2 Plan Simulations |
Aug-2009 |
77 pages |
| Authors:
Jennifer N Tate; Cassandra G Ross; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
|
 | This report documents the results of several plan scenarios on the sedimentation behavior in the Houston-Galveston Ship Channel area. The U.S. Army Engineer District, Galveston, recently enlarged the Houston Ship Channel in depth and width. Preliminary evaluations of the enlarged channel indicate a higher than anticipated rate of deposition in the channel reach near Atkinson Island. A Coastal and Hydraulics Laboratory investigation (Tate and Berger 2006) was charged with determining ... |
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| Fokker-Planck Model for Thermal Smoothing in Inhomogeneous Laser-Matter Interactions |
24-Jul-2009 |
16 pages |
| Authors:
Michael J Keskinen; NAVAL RESEARCH LAB WASHINGTON DC
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| Using a fully kinetic 2D Fokker-Planck model, the generation and evolution of ion density perturbations from nonuniform laser deposition in a plasma slab have been studied. It is found that significant smoothing of the ion density perturbations from nonuniform optically smoothed single beam laser deposition can be achieved on hydrodynamic time scales over a long range of scale sizes. In addition, it is observed that the Fokker-Planck model predicts more ... |
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| Simulation of Ballistic Impact of a Tungsten Carbide Sphere on a Confined Silicon Carbide Target |
Jun-2009 |
16 pages |
| Authors:
C G Fountzoulas; B A Cheeseman; J C LaSalvia; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| The present investigation is a continuation of our previous study on the ability of the phenomenological Johnson-Holmquist model to predict the observed damage induced by spheres of tungsten carbide (WC) striking confined cylinders of silicon carbide (SiC) at velocities between 63 m/s to 500 m/s. In this study, the WC was modeled using the Johnson-Cook plasticity model along with a principal stress failure criterion calibrated with recently available experimental data. ... |
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| Hydrodynamic Design of a Dead Weight Anchor Device Optimized for Station Keeping and Suppression of Subsequent Burial on Sedimentary Beds in Coastal Environments |
31-Mar-2009 |
10 pages |
| Authors:
Gerald D'Spain; Scott Jenkins; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
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| Simulations of station keeping and burial of a dead weight anchor device were performed using the Vortex Lattice Mine Burial/Migration Model (VORTEX). The VORTEX model was developed at Scripps Institution of Oceanography under previous ONR funding, (Inman and Jenkins, 2002; Jenkins and Inman 2002, Jenkins and Wasyl 2006). This model has been validated in field experiments conducted under ONR's Mine Burial Program. |
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| Heterogeneous Teams of Autonomous Vehicles: Advanced Sensing & Control |
Mar-2009 |
14 pages |
| Authors:
Larry P Atkinson; OLD DOMINION UNIV NORFOLK VA DEPT OF OCEAN EARTH AND ATMOSPHERIC SCIENCES
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| Initial collaborative observations and modeling of a warm effluent plume (Calvert Cliffs Nuclear Power Plant) suggest that coherence length scales in both models and observations are similar leading to confidence in the models for AUV decision making. Studies were initiated to determine if algorithms could be developed that could process current fields and find regions of very low current speed. Tests of the algorithm on a two-dimensional simulated velocity field ... |
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| Lift and Drag Performance of Odontocete Cetacean Flippers |
Jan-2009 |
11 pages |
| Authors:
Frank E Fish; Paul W Weber; Laurens E Howle; Mark M Murray; DUKE UNIV DURHAM NC DEPT OF MECHANICAL ENGINEERING AND MATERIALS SCIENCE
|
| Cetaceans (whales, dolphins and porpoises) have evolved flippers that aid in effective locomotion through their aquatic environments. Differing evolutionary pressures upon cetaceans, including hunting and feeding requirements, and other factors such as animal mass and size have resulted in flippers that are unique among each species. Cetacean flippers may be viewed as being analogous to modern engineered hydrofoils, which have hydrodynamic properties such as lift coefficient, drag coefficient and associated ... |
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| Dynamic Length-Scale Characterization and Nonequilibrium Statistical Mechanics of Transport in Open-Cell Foams |
Jan-2009 |
5 pages |
| Authors:
Tyler R Brosten; Sarah L Codd; Robert S Maier; Joseph D Seymour; MONTANA STATE UNIV BOZEMAN DEPT OF MECHANICAL ENGINEERING
|
| Nuclear magnetic resonance measurements of scale dependent dynamics in a random solid open-cell foam reveal a characteristic length scale for transport processes in this novel type of porous medium. These measurements and lattice Boltzmann simulations for a model foam structure indicate dynamical behavior analogous to lower porosity consolidated granular porous media, despite extremely high porosity in solid cellular foams. Scaling by the measured characteristic length collapses data for different foam ... |
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| Demonstration of an Integrated Compliance Model for Predicting Copper Fate and Effects in DoD Harbors |
Dec-2008 |
140 pages |
| Authors:
D B Chadwick; I Rivera-Duarte; G Rosen; P Wang; R C Santore; A C Ryan; P R Paquin; S D Hafner; W Choi; SPACE AND NAVAL WARFARE SYSTEMS CENTER PACIFIC SAN DIEGO CA
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| The Environmental Security Technology Certification Program supported Project ER-0523 on the demonstration of an integrated modeling system that provides an improved methodology for achieving copper compliance in harbors. This model is consistent with the current regulatory framework based on the Biotic Ligand Model (BLM) for freshwater. The integrated model has two components, the seawater-BLM (developed as part of this project), and the existing hydrodynamic transport and fate algorithm, Curvilinear Hydrodynamics ... |
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| Resistance and Component Hull Interactions of a High-Speed Trimaran Sealift Ship |
Nov-2008 |
101 pages |
| Authors:
Jonathan Slutsky; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD HYDROMECHANICS DIRECTORATE
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| Multi-hull vessels potentially offer several advantages over conventional monohull ship designs for a variety of operational requirements. Predicting the nature and extent of the interaction between the component hulls is a complex hydrodynamic issue. In this experiment, a resistance model test of high-speed sealift trimaran was performed, varying the position and angle of the side hulls relative to the center hull. Forces on the side hulls were measured in addition ... |
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| The Gulf Stream Pathway and the Impacts of the Eddy-Driven Abyssal Circulation and the Deep Western Boundary Current |
06-Jul-2008 |
33 pages |
| Authors:
Harley E Hurlburt; Patrick J Hogan; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| A hydrodynamic model of the subtropical Atlantic basin and the Intra-Americas Sea (9-47 deg N) is used to investigate the dynamics of Gulf Stream separation from the western boundary at Cape Hatteras and its mean pathway to the Grand Banks. The model has five isopycnal Lagrangian layers in the vertical and allows realistic boundary geometry, bathymetry, wind forcing, and a meridional overturning circulation (MOC), the latter specified via ports in ... |
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| Southeast Oahu Coastal Hydrodynamic Modeling with ADCIRC and STWAVE |
01-Jul-2008 |
61 pages |
| Authors:
Jane M Smith; Mary A Cialone; Mitchell E Brown; Kent K Hathaway; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| This study provides the Honolulu District (POH) with numerical modeling tools for understanding nearshore circulation and sediment transport for Southeast Oahu (SEO). Circulation and wave models are developed and validated for this region and can be applied to assess sediment transport potential for various forcing conditions and to determine the likelihood of accretional and erosional areas within the model domain. Application of a wave model includes the generation of a ... |
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| Assessment of Proposed Wave Barriers for 5T Small Boat Basin at Naval Station Norfolk Virginia |
Jul-2008 |
47 pages |
| Authors:
Erick T Huang; Hamn-Ching Chen; NAVAL FACILITIES ENGINEERING SERVICE CENTER PORT HUENEME CA
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| This task assesses the dynamic responses of a small boat basin to local storms and quantifies the performance of a proposed breakwater. The assessment procedure adopts a sophisticated Computational Fluid Dynamic model capable of preserving the exact site condition and all prevailing hydrodynamic mechanisms at high accuracy. This exercise clearly illustrates the feasibility and merits of modern simulation models for designs. The results confirm that this basin is sensitive to ... |
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| Re-Visiting 1-D Hypervelocity Penetration (Preprint) |
01-Apr-2008 |
13 pages |
| Authors:
David E Lambert; AIR FORCE RESEARCH LAB EGLIN AFB FL MUNITIONS DIRECTORATE
|
| Classical, one-dimensional theory of hydrodynamic penetration is used as the basis of establishing simplified analytical relationships describing energy, momentum, and power deposition during hypervelocity impact events. A concise overview of the 1-D model is given followed by a select grouping of terms into relationships that offer first-order criteria for making engineering design considerations on relevant applications and assist in the analysis of experimental observations. Momentum, energy, and power deposition are ... |
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| CFD Analysis of a Penta-Hulled, Air-Entrapment, High-Speed, Planning Vessel |
MAR 2008 |
211 pages |
| Authors:
Edward R. Fultz; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The objective of this thesis is to analyze the hydrodynamic properties of a specialized pentahulled, air entrapment, high-speed planning vessel. Due to the unique features of this hull, a multi-layered approach based on computational fluid dynamics was adopted. The first is a steady state model with no free surface effects. It determines the lift and drag on the hull at a fixed waterline. It does not capture any of the ... |
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| Nonhydrostatic Hindcasts of High Amplitude Internal Waves in the Mid-Atlantic Bight |
30 JAN 2008 |
6 pages |
| Authors:
Patrick C. Gallacher; Michael Schaferkotter; William E. Avera; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| From late July to early September 2006 an intense field program, Shallow Water 2006 (SW06), was conducted in the Mid-Atlantic Bight (MAB) off of the New Jersey coast The goal of the program is to the determine the environmental processes that affect shallow water acoustic propagation and scattering and to understand the dynamics of the generation and evolution of those processes a phenomena that dominates much of the hydrodynamics in ... |
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| The Community Sediment Transport Modeling System |
Jan-2008 |
|
| Authors:
Timothy Keen; W R Geyer; Christopher R Sherwood; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| The goal of the Community Sediment Transport Modeling System (CSTMS) is to produce an open source model that couples hydrodynamics (circulation and waves), sediment transport, and morphodynamics. The model is intended to be used as both a research tool and for practical applications. An accurate and useful model requires coupling sediment-transport with hydrodynamic forcing and stratigraphic evolution. Ultimately, the modeling system will consist of interoperable modules, conforming to a community-accepted ... |
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| High Reynolds Number Micro-Bubble and Polymer Drag Reduction Experiments |
JAN 2008 |
183 pages |
| Authors:
Steven L. Ceccio; David R. Dowling; Marc Perlin; Michael Solomon; MICHIGAN UNIV ANN ARBOR DEPT OF MECHANICAL ENGINEERING
|
| This effort was a continuation of the joint ONR and DARPA programs of the PI and Co-PI's, initiated as part of the DARPA Friction Drag Reduction Program (ATO/TTO). The purpose of the investigation was to examine the physics and engineering of friction drag reduction methods for turbulent boundary layers (TBL) found in hydrodynamic flows. Three methods of friction drag reduction (FDR) were examined: * Polymer Drag Reduction * Micro-bubble Drag ... |
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| Ocean Wave Energy Harvesting Devices |
JAN 2008 |
|
| Authors:
Jeffrey T. Cheung; Earl F. Childress III; TELEDYNE SCIENTIFIC AND IMAGING LLC THOUSAND OAKS CA
|
| Development of a mechanically sound buoy design. which generated 10W average power in Beaufort Sea State I. and showed potential for up to 20W in Sea State 4. Development of a wave energy harvesting buoy capable of generating 2W in Sea State I. and with proper mechanical alignment able to generate over 4W. Development of two modeling capabilities: a classical mechanical model used lbr optimizing the electromagnetic design,. and a ... |
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| Cumulative Effects of Channel and EBB Shoal Dredging on Inlet Evolution in Southwest Florida, USA |
Jan-2008 |
14 pages |
| Authors:
Nicholas C Kraus; Mohamed A Dabees; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| This paper describes analysis and numerical modeling of tidal inlets in southwest Florida, where coverage of large temporal and spatial scales is necessary. A methodology is introduced for examining the response of complex inlet systems to dredging, including modeling of regional hydrodynamics, wave-current interaction, sediment transport, and application of the Inlet Reservoir Model. A case study for Longboat Pass, Florida, demonstrates this methodology. Longboat Pass is one of several tidal ... |
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| Development of Electron Beam Pumped KrF Lasers for Fusion Energy |
2008 |
18 pages |
| Authors:
J. D. Sethian; M. Friedman; J. Giuliani; R. H. Lehmberg; M. Myers; S. P. Obenschain; M. Wolford; P. Kepple; F. Hegeler; S. Swanekamp; NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV
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| Direct drive with krypton fluoride (KrF) lasers is an attractive approach to inertial fusion energy (IFE): KrF lasers have outstanding beam spatial uniformity, which reduces the seed for hydrodynamic instabilities; they have short wavelength (248 nm) that increases the rocket efficiency and raises the threshold for deleterious laser-plasma instabilities; they have the capability for zooming , i.e. decreasing the spot size to follow an imploding pellet and thereby increase efficiency; ... |
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| Influence of Surface Roughness on Polymer Drag Reduction |
30 NOV 2007 |
25 pages |
| Authors:
Steven L. Ceccio; David R. Dowling; Marc Perlin; Michael Solomon; MICHIGAN UNIV ANN ARBOR DEPT OF MECHANICAL ENGINEERING
|
| This effort accompanied the DARPA Friction Drag Reduction Program (ATO/TTO) effort at the University of Michigan funded under contract HR-0011-04-1-001 "High Reynolds Number Micro-bubble and Polymer Drag Reduction Experiments" for flows over smooth surfaces. The details of that effort can be found in the final technical report for that project. The purpose of the additional investigation was to examine the physics and engineering of friction drag reduction methods for turbulent ... |
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| Expanded Simulation Models "Version 3.0" for Growth of the Submerged Aquatic Plants American Wildcelery, Sago Pondweed, Hydrilla, and Eurasian Watermilfoil |
NOV 2007 |
25 pages |
| Authors:
Elly P. Best; William A. Boyd; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS ENVIRONMENTAL LAB
|
| This technical note describes modifications of simulation models for growth of four submersed aquatic vegetation (SAV) types, greatly expanding their application potential. The modifications include descriptions of the vegetation responses to daily changes in current velocity and epiphyte shading, and accommodation of daily changes in water level. These models can be used to evaluate key environmental conditions in which SAV would persist under a variety of management scenarios within the ... |
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| Measuring the Spatial Distribution of Ripples Using REMUS AUV |
10 OCT 2007 |
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| Authors:
Wayne R. Geyer; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF APPLIED OCEAN PHYSICS AND ENGINEERING
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| The long term goal of this work is to increase our understanding of bedform geometry and processes associated with bedforms on the continental shelf. To do this we have been developing novel measurement techniques, conducting observations of both the spatial and temporal variability of ripples and developing a variety of model approaches. |
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| Using a Near-Bed Sediment Flux Sensor to Measure Wave Formed Bedform Migrations and Formation Processes |
OCT 2007 |
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| Authors:
Peter A. Traykovski; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
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| My research program focuses on identifying and quantifying sediment erosion, transport, and deposition processes on the continental shelf through state of the art observational techniques in both fine grained and sandy environments. In sandy environments, my goal is to understand the detailed interactions and feedbacks between hydrodynamics, bedforms, and the resulting sand transport. In fine-grained environments, I have been investigating the role fluid mud flows as a depositional mechanism in ... |
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| Multi-Camera, High-Speed Imaging System for Kinematics Data Collection |
21 SEP 2007 |
14 pages |
| Authors:
Jason Geder; William C. Sandberg; Ravi Ramamurti; NAVAL RESEARCH LAB WASHINGTON DC
|
| A two-camera system was devised and created to determine the kinematics of flapping fin and flapping wing vehicles. Each camera is set up to capture triggered, high-speed (up to 10,000 frames per second) images of the appendage in a test environment. Using direct linear transforms, each camera is calibrated to convert image coordinates to an alternate coordinate system. Points of interest on the appendage are selected from each camera image ... |
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| Application of a Water Quality Model to Mississippi Sound to Evaluate Impacts of Freshwater Diversions |
SEP 2007 |
889 pages |
| Authors:
Mark S. Dortch; Mansour Zakikhani; Mark R. Noel; Sung-Chan Kim; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS ENVIRONMENTAL LAB
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| This report describes the development and application of a water quality model to the Mississippi Sound region to address the impacts of various freshwater diversion alternatives. The CH3D-Sigma (sigma level vertical coordinates) model code was the hydrodynamic model that was used to provide transport fluxes for the CE-QUAL-ICM water quality model. The model domain also included Mobile Bay, the Mississippi coastal bays, Lakes Pontchartrain and Borgne, Biloxi Marsh, and part ... |
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| Thrust Breakdown Characteristics of Conventional Propellers |
SEP 2007 |
51 pages |
| Authors:
Scott D. Black; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD PROPULSION AND FLUID SYSTEMS DIV
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| Historically, the Burrill diagram has been used early in the propeller design process to estimate the inception of thrust loss due to cavitation. That data was based on a systematic series of propeller tested in a uniform inflow. This report develops an alternative set of curves based on five modern propeller designs to estimate thrust breakdown for both uniform inflow and for a range of non-uniformities. |
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| Sea Clutter Generation and Target Detection |
JUL 2007 |
26 pages |
| Authors:
Stefano M. Canta; Danilo Erricolo; ILLINOIS UNIV AT CHICAGO CIRCLE COLL OF ENGINEERING
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| Propagation model for the electromagnetic field that accounts for the clutter and metallic objects in the sea. Computationally fast, and the complete work will include electromagnetic propagation models and vector antennas. |
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| Morphologic Modeling of Multiple Barrier Island Breaches for Regional Application |
01-May-2007 |
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| Authors:
Kenneth J Connell; Magnus Larson; Nicholas C Kraus; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| This paper introduces a time-dependent model of regional barrier island breaching for multiple openings, whether as permanent inlets or as new breaches to the same bay. The model allows an arbitrary number of breaches and is forced by tide, storm surge, and wave set up. Limitations on the hydrodynamics, hence calculated breach evolution, are those associated with the Keulegan inlet model. The model includes possible closure or limited breaching by ... |
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| A Method to Predict Atomization Performance in Gas-Centered Swirl-Coaxial Injectors |
27 MAR 2007 |
11 pages |
| Authors:
M. D. Lightfoot; S. A. Danczyk; D. G. Talley; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| The ability to predict atomizer performance can reduce the cost of system development in many areas. This paper investigates the atomization efficiency and droplet distribution from films with strong gas-phase influences. A prediction of atomization efficiency based on a general theory of the droplet creation process is given. In this process a disturbance is created on the film surface then broken down into droplets via stripping. The theory relates the ... |
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| Naval Research Laboratory Ecological -- Photochemical -- Bio-optical--Numerical Experiment (Neptune) Version 1: A Portable, Flexible Modeling Environment Designed to Resolve Time-dependent Feedbacks Between Upper Ocean Ecology, Photochemistry, and Optics |
21 FEB 2007 |
52 pages |
| Authors:
Jason K. Jolliff; John C. Kindle; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| A modeling system has been constructed that combines ecological element cycling, photochemical processes, and bio-optical processes into a single simulation that may be coupled to hydrodynamic models that provide temperature fields as well as the advection/diffusion of state variables. The model is derived from a history of ocean biogeochemical models that describe the transformation of elemental reservoirs (carbon, nitrogen, phosphorus) based upon lower-trophic order ecosystem function. The model description of ... |
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| Implementing a Low-Cost Long-Range Unmanned Underwater Vehicle: The SeaDiver Glider |
09 JAN 2007 |
79 pages |
| Authors:
David Gassier; Jerome Rebollo; Romain Dumonteil; NAVAL POSTGRADUATE SCHOOL MONTEREY CA MODELING VIRTUAL ENVIRONMENTS AND SIMULATION
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| The SeaDiver Glider is an UUV (Unmanned Underwater Vehicle) used for underwater prospecting at a low cost with a long distances coverage (approx = 1400 miles). It moves without propellers by changing its buoyancy with the help of ballast and its hydrodynamics profile reminiscent of a wing (model NACA0022). Ballast inflation makes it raise the surface, ballast deflated make it submerge the bottom. Ballast is positioned in front of its ... |
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| Direct-Drive Laser Target Designs for Sub-MegaJoule Energies |
01-Jan-2007 |
11 pages |
| Authors:
A L Velikovich; J H Gardner; A J Schmitt; D G Colombant; S T Zalesak; D E Fyfe; S P Obenachain; J W Bates; W Manheimer; NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV
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| New direct-drive laser target designs with KrF laser light take advantage of the shorter wavelength to lower the laser energy required for substantial gain (>30x) to sub-MJ level. These low laser-energy pellets are useful in systems that could form an intermediate step towards fusion energy, such as the proposed Fusion Test Facility [S. P. Obenschain,et al, Phys. Plasmas 13, 056320 (2006)]. The short wavelength laser should allow higher intensity (and ... |
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| Nematic Liquids in Weak Capillary Poiseuille Flow: Structure Scaling Laws and Effective Conductivity Implications |
01-Jan-2007 |
19 pages |
| Authors:
Hong Zhou; M G Forest; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MATHEMATICS
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| We study the scaling properties of heterogeneities in nematic (liquid crystal) polymers that are generated by pressure-driven, capillary Poiseuille flow. These studies complement our earlier drag-driven structure simulations and analyses. We use the mesoscopic Doi-Marrucci-Greco model, which incorporates excluded-volume interactions of the rod-like particle ensemble, distortional elasticity of the dispersion, and hydrodynamic feedback through orientation dependent viscoelastic stresses. The geometry likewise introduces anchoring conditions on the nano-rods which touch the ... |
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| Mine Burial Experiments at the Martha's Vineyard Coastal Observatory |
Jan-2007 |
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| Authors:
Peter Traykovski; Larry A Mayer; Michael D Richardson; James D Irish; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
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| Several experiments to measure post impact burial of seafloor mines by scour and fill have been conducted near the Woods Hole Oceanographic Institution's Martha's Vineyard Coastal Observatory (MVCO, Edgartown, MA). The sedimentary environment at MVCO consists of a series of rippled scour depressions (RSDs), which are large scale bedforms with alternating areas of coarse and fine sand. This allows simultaneous mine burial experiments in both coarse and fine sand under ... |
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| Measured and Predicted Burial of Cylinders During the Indian Rocks Beach Experiment |
Jan-2007 |
13 pages |
| Authors:
Sean Griffin; Edward F III; Braithwaite; Paul A Elmore; Kevin B Briggs; Grant R Bower; Thomas F Wever; Michael D Richardson; John Bradley; Ralf Luhder; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
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| Burial of instrumented mine-like cylinders as a result of wave-induced scour was measured during experiments conducted in shallow water (15-16 m) with fine-sand (133-um) and coarse-sand (566-um) sediments off Indian Rocks Beach (IRB), FL. Scour pits developed around the instrumented cylinders in the fine-sand site when significant wave heights exceeded 2 m, causing the cylinders to pitch, then roll into the developing scour pits, often changing heading to align parallel ... |
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| Multibeam Observations of Mine Burial Near Clearwater, FL, Including Comparisons to Predictions of Wave-Induced Burial |
Jan-2007 |
17 pages |
| Authors:
Michael D Richardson; Monica L Wolfson; David F Naar; Peter A Howd; Stanley D Locker; Brian T Donahue; Carl T Friedrichs; Arthur C Trembanis; Thomas F Wever; UNIVERSITY OF SOUTH FLORIDA SAINT PETERSBURG
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| A Kongsberg Simrad EM 3000 multibeam sonar (Kongsberg Simrad, Kongsberg, Norway) was used to conduct a set of six repeat high-resolution bathymetric surveys west of Indian Rocks Beach (IRB), just to the south of Clearwater, FL, between January and March 2003, to observe in situ scour and burial of instrumented inert mines and mine-like cylinders. Three closely located study sites were chosen: two fine-sand sites, a shallow one located in ... |
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| Evaluation of Delft3D Performance in Nearshore Flows |
28 DEC 2006 |
27 pages |
| Authors:
Y. L. Hsu; James D. Dykes; Richard A. Allard; James M. Kaihatu; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| The Delft3D modeling system, developed by Delft Hydraulics (www.wldelft.nl) is capable of simulating hydrodynamic processes due to waves, tides, rivers, winds, and coastal currents. It can be used to provide surf prediction for areas with complicated bathymetry where the use of a one-dimensional surf model is inappropriate. Delft3D has many model options and free parameters. The main objective of this investigation is to examine the effects of these selections on ... |
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| Analysis and Modeling of Surfzone Turbulence and Bubbles |
29 NOV 2006 |
6 pages |
| Authors:
Falk Feddersen; SCRIPPS INST OF OCEANOGRAPHY LA JOLLA CA INTEGRATIVE OCEANOGRAPHY DIV
|
| Turbulence in the surfzone and nearshore mixes momentum vertically, transmits stress to the sea bed, influences the structure of the cross- and alongshore currents, and controls the suspension of sediment from the sea bed. In many coastal and shelf environments, the sea-bed is the primary source of turbulence due to bottom induced shear. In the surfzone, the breaking-wave generated turbulence likely dominates over bottom generated turbulence. However, the dynamics of ... |
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| Impeller Volute and Diffuser Interaction |
01-Nov-2006 |
29 pages |
| Authors:
G Pavesi; PADOVA UNIV (ITALY)
|
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| Single High Fidelity Geometric Data Sets for LCM - Model Requirements |
NOV 2006 |
100 pages |
| Authors:
D. Brennan; T. Koko; K. Mackay; M. Norwood; S. Tobin; E. TENG; J. Wallace; MARTEC LIMITED HALIFAX (NOVA SCOTIA)
|
| Over the past decade, the ship building industry has begun to develop and use Single Product Models (SPMs) for improving the management and efficiency of design, analysis and construction of commercial and naval vessels. SPMs are extensive single 3D CAD data models incorporating hull structure, propulsion, steering, piping, electrical, HVAC and other systems, which make up a complete ship. Ship classification societies and navies (most notably the USN in their ... |
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| Simulation of Supersonic Base Flows: Numerical Investigations Using DNS, LES, and URANS |
OCT 2006 |
342 pages |
| Authors:
Hermann F. Fasel; Richard D. Sandberg; ARIZONA UNIV TUCSON DEPT OF AEROSPACE AND MECHANICAL ENGINEERING
|
| Transitional and turbulent supersonic axisymmetric wakes were investigated by conducting various numerical experiments. The main objective was to identify hydrodynamic instability mechanisms in the flow at Mach number M = 2.46 for several Reynolds numbers, and relating these to coherent structures that are found from various visualization techniques. The premise for this approach is the assumption that flow instabilities lead to the formation of coherent structures. The effect of these ... |
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| Smoothed Particle Hydrodynamics: Applications Within DSTO |
OCT 2006 |
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| Authors:
D. A. Jones; D. Belton; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) PLATFORM SCIENCES LAB
|
| Smoothed Particle Hydrodynamics (SPH) is a computational technique for the numerical simulation of the equations of fluid dynamics without the use of an underlying numerical mesh. Although originally developed for use in astrophysical gas dynamics, SPH has recently been applied to many other areas of numerical fluid dynamics and materials modelling, several of which have particular relevance to defense problems of interest to the DSTO. In this report we review ... |
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| Functional Objectives for Stream Restoration |
SEP 2006 |
19 pages |
| Authors:
J. C. Fischenich; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
|
| The National Research Council (1996) defined restoration as "the return of the form and function of an ecosystem to its predisturbance condition..." This definition presents two challenges when working in today's environment. First, the significant hydrological changes and infrastructure encroachments found in many watersheds often prevent the reestablishment of the stream form to a condition prior to disturbance. These streams have a new form consistent with the altered conditions, and ... |
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| Breach History and Susceptibility Study, South Jetty and Navigation Project, Grays Harbor, Washington |
SEP 2006 |
242 pages |
| Authors:
Ty V. Wamsley; Mary A. Cialone; Kenneth J. Connell; Nicholas C. Kraus; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| The purpose of this study was to analyze the December 1993 breach at Grays Harbor, WA, and assess the threat to the Federal Navigation Project had the breach not been filled the following fall. The study was conducted by quantifying evolution of breach morphology; numerically simulating the ocean wave and water level conditions producing the current through such a breach, including investigation of wide-area implications for the current in Grays ... |
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| Enhanced Numerical Modeling of Breaking Waves |
SEP 2006 |
15 pages |
| Authors:
Richard Leighton; GENERAL DYNAMICS YPSILANTI MI ADVANCED INFORMATION SYSTEMS
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| Hydrodynamic predictions of waves can be made via numerical solution of the Navier-Stokes equations subject to the appropriate free-surface boundary conditions. For practical flow of naval hydrodynamic interest, simplifications to these equations must be made in order to make the computations feasible. Two approaches for this exist: potential flow, where viscous and rotational effects are formally eliminated from the equations, and Reynolds-averaged approaches, where the equations are time-averaged. Potential flow ... |
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| Matagorda Ship Channel, Texas: Jetty Stability Study |
AUG 2006 |
165 pages |
| Authors:
Nicholas C. Kraus; Lihwa Lin; Brian K. Batten; Gary L. Brown; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| The entrance of the Matagorda Ship Channel, connecting the Gulf of Mexico to Matagorda Bay, Texas, has experienced a strong currents since its construction in 1963-1964. Strong currents had been predicted in physical model experiments performed during design to determine the optimal location of the new inlet cut through Matagorda Peninsula and entrance configurations. The current has produced a large area of scour on the bay side of the inlet ... |
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| Including Nearshore Processes in Phase-Averaged Hydrodynamics Models |
AUG 2006 |
47 pages |
| Authors:
Bradley D. Johnson; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| The large spatial and time scales of the numerical modeling projects of the U.S. Army Corps of Engineers (USACE) requires the use of computationally efficient phase-averaged hydrodynamic models derived by averaging the equations of motion over a representative short wave period. Guidance in modeling nearshore regions with phase-averaged hydrodynamic models is provided herein. Physical processes unique to the surf zone are described along with methods of incorporating these effects to ... |
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| Conceptual Processes for Linking Eutrophication and Network Models |
AUG 2006 |
16 pages |
| Authors:
Dorothy H. Tillman; Carl F. Cerco; Mark R. Noel; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
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| This three-year study investigates the coupling of eutrophication and network models, applies the results to a specific problem, and recommends a general procedure for future endeavors in this area. |
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Reports by Keyword(s)
HYDRODYNAMICS
